He said: "I shaved (my head) months before to see what it would look like and turned up on the shoot with about two month's growth and they were like, 'What have you done?' and I had to have the first of 17-hour hair extensions sessions.

"When we finally shaved it off we decided to FaceTime Patrick Stewart so he could pass on the baldy baton.

"We though it was funny when he asked if he could have some of the hair, but it turns out the director bagged it up for him and he now has all my hair at home in a safe, which is kind of creepy."

Jennifer Lawrence and James McAvoy at a global fan screening of X-Men Apocalypse in LondonCredit:
Will Oliver/EPA

However, McAvoy told Norton that he would be on board to make more X-Men films.

"If they write good stuff for us, if schedules work out and they pay enough money I am sure we'll still keep doing it," he said.

On the same show, Lawrence revealed an embarrassing encounter with Harrison Ford that left her "more humiliated than ever before".

The actress said she was on a night out with British comedian Jack Whitehall when the two spotted Star Wars actor Ford and director JJ Abrams and she mistakenly thought they would know who she was.

"I probably humiliated myself more than ever before," she told Norton. "I never assume anyone knows who I am, but when I spotted Harrison Ford and JJ Abrams I was like, 'It'll be fine, we're all co-workers, right!'

"So I went up to them and started dancing like an idiot and the whole table just went quiet and stared at me.

"I realised while I am dancing that they had absolutely no idea who I was so I just turned around and walked back to Jack dying of embarrassment."

She added: "Later (Ford) wrote to me because someone with a 12-year-old must have told him who I was!"

From left: Johnny Depp, Jennifer Lawrence, Graham Norton, James McAvoy, Jack Whitehall and Will.i.am during filming of the Graham Norton Show Credit:
PA Images on behalf of So TV

Whitehall called it "probably the best night of my life and Jen's worst" when, in an awkward twist, Ford did recognise him as the two had just filmed a show together.

He said: "Jen had just been blanked and I was like, 'Hey, it's alright, I'll go and say hi to Harrison,' and everyone was like, 'Jack, don't do this. It will be humiliating.'

"I get up and walk over thinking, 'Oh God, maybe he won't remember me and I'm going to be humiliated too.'

"And literally as I walked over he stood up and shouted, 'Hey, Jack!' It was so funny.

Lawrence has a reputation for putting her foot it in and also revealed she owed a long-overdue apology to Sandra Bullock after she insulted her at the Oscars.

She said: "I still feel bad. I should have emailed her and explained but I don't know what to say.

"I was back stage with her at the Oscars where she was presenting and I said, 'I love all your work except All About Steve - it was really bad.'

"She was lovely about it but as she walked on stage I shouted after her, 'Don't suck, Sandy!' I still have no idea why."